body{
    margin: 0;
    padding: 0;
    .box{
        width: 300px;
        height: 550px;
        border: 1px solid #f00;
        margin: 0 auto;
        overflow-y: scroll;
        .scroll_box{
            width: 100%;
            overflow: hidden;
            .demo{
                width: 100%;
                height: 55px;
                overflow: hidden;
                h1,h2{
                    margin: 0;
                    padding: 0;
                    font-weight: normal;
                    font-size: 16px;
                }
            }
        }
    }
}